Carrier 48KHA - Manual (Page 5)

COMBUSTION-AIR SHROUD
CONTROL
TRANSFORMER
COMPRESSOR
CONTACTOR
GAS INLET
PRESSURE TAP
(BACK SIDE)
‘GAS PIPE
ENTRANCE HOLE
LOW VOLTAGE SECONDARY p. pf'TpoNIC \
WIRES
air SHIELD ^^) n 7 r OL GAS VALVE
HEAD
REGULATOR
ADJUSTING SCREW
Fig. 5—Vent Cap Assembly
Fig. 6—Model 48KLA136—Side View
(Partiai) with Access Doors Removed
2. Protect all segments of piping system against physiceJ
and thermal deimage. Support all piping with appropri­
ate hangers, etc. Use a minimum of one hanger in every
6 feet. For pipe sizes larger them V
2
-in., follow recom­
mendations of national codes.
Apply joint compound (pipe dope) speiringly and only
to male threads of joint when meiking pipe connections.
Use only pipe dope that is resistant to action of lique­
fied petroleum gases as specified by local and/or
nationeJ codes. Never use pipe thread tape.
InsteJl a sediment trap in riser leading to the heating
section. See Fig. 7. This drip leg functions as a trap for
dirt and condensate. Install trap where condensate can­
not freeze. Install this sediment trap by connecting a
piping tee to riser leading to heating section, so that
straight-through section of tee is vertical. Then, con­
nect capped nipple into lower end of tee. Extend
capped nipple below level of gas controls.
3.
4.
Step 2—Make Gas Piping Connections—A manual shutoff
vedve is shipped loose in the burner compartment or blower
compartment. Connect one end of a field-supplied V
2
-in.
streught nipple to the gas valve inlet. Connect the other end
of the nipple to the manual shutoff valve as shown in Pig. 6.
The gas supply pipe enters unit through access hole pro­
vided. See Fig. 4 for location. The gas connection to unit is
made to the V
2
-in. FPT gas inlet on manual shutoff. See Fig.
6 for inlet location.
Install a separate gas supply line that runs directly from
meter to heating section. Do not use cast-iron pipe. Check
local utility for recommendations concerning existing lines.
Choose a supply pipe that is large enough to keep pressure
loss as low as practical. Never use pipe smaller than the ^¡¿-in.
FPT gas inlet on unit manual shutoff.
When installing gas supply line, observe local codes pertain­
ing to gas pipe installations. Refer to National Fuel Gas
Code, NFPA 54-1984/ANSI Z223.1-1984 in absence of local
building codes. Adhere to following pertinent recom­
mendations:
1. Avoid low spots in long runs of pipe. Grade all pipe %-
in. in every 15 ft to prevent traps. Grade all horizonteJ
runs downward to risers. Use risers to connect to heat­
ing section and to meter.
Fig. 7—Sediment Trap
5. Install an accessible, external, manual shutoff valve in
gas supply pipe within 6 ft of heating section.
NOTE: The unit manual shutoff valve has a Vs-in. tap­
ping on the inlet side of this shutoff for measuring gas
input pressure.
6. Install ground-joint union close to heating section
between unit manual shutoff and external manual main
shutoff valve.